Vermiculite, Old Oil Tanks and Lead Pipes in Older Markham Homes

Neeraj Moolchandani is a top real estate agent in Markham, Ontario. Published November 13, 2026 · By Neeraj Moolchandani, REALTOR®, Cofounder of the Kaizen Real Estate Team, eXp Realty, Brokerage

Century homes and mid century houses in Markham Village, heritage Unionville and the Markham side of Thornhill have charm that new homes cannot copy. They can also carry hidden legacy materials. Our Kaizen Real Estate Team is one of the teams Markham buyers trust with older homes, and our guide on aluminum wiring, Poly B and ice dams covers 1970s and 1980s issues. This post focuses on older ones.

At a Glance

Vermiculite Insulation

Vermiculite is a pebble like, grey brown or gold insulation often found poured between attic joists. Health Canada says most vermiculite insulation came from a mine in Libby, Montana, sold mostly as Zonolite, and that it is prudent to assume vermiculite produced before 1990 may contain some asbestos.

Health Canada advises that the best way to reduce risk is not to disturb it, and that insulation sealed behind walls and floors poses very little risk. Problems arise during renovation. If you plan attic work, a professional test and, if needed, professional removal come first.

Buried Fuel Oil Tanks

Many older homes once heated with oil. When owners switched to gas, some tanks were left in the ground. TSSA says Ontario regulations require an unused underground tank to be removed, and that only a TSSA registered petroleum contractor may remove it. Owners are responsible for the cost. In some cases TSSA can grant a variance to leave a tank in place, but that requires an environmental assessment.

• Look for an old fill pipe or vent pipe near the foundation.
• Look for capped lines through the basement wall.
• Ask the seller whether the home ever used oil heat, and for any removal records.
• Ask your insurer early; many will not insure a home with a buried tank.

Lead Water Pipes

Markham's tap water page says lead was used for residential water service lines before 1953, and that all known lead service lines from the watermain to the property line have been replaced. The City's responsibility ends at the property line, so a lead pipe can remain on the private side, from the property line into the house. Markham's water also receives phosphate treatment, which helps reduce lead from pipes.

• Look at the pipe where it enters the basement: lead is dull grey and soft, and a key scratch shows shiny silver.
• Ask the seller whether the private line was replaced.
• Consider a lead test, and budget for replacing the private line if needed.
• Call Markham's Contact Centre if you think the home is connected to lead.

How to Buy Safely

1. Include a home inspection condition and tell the inspector the home's age.
2. Ask specifically about attic insulation, oil heat history and the water service pipe.
3. Get insurance quotes before you firm up.
4. If an issue appears, get written quotes from qualified contractors during the condition period.
5. Use the quotes to negotiate price or a credit.

Our inspection checklist covers the rest, and our guide on heritage district homes explains extra approvals.

If You Are Selling an Older Home

Buyers and their lenders will ask. Gather records of any insulation removal, tank removal and pipe replacement, and be honest about what you know. A home with documented fixes is far easier to sell than one with open questions. Ask your lawyer about your disclosure obligations.

Questions Markham Clients Ask

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